XenITH: Xen in the Hand

Usability and portability have been key commercial drivers for increasingly capable handheld devices, which have been enabled by advances in Moore’s Law and well as in wireless systems. The nature of such devices makes them extremely personal, and yet they offer an untapped resource for new forms of peer-to-peer and cooperative communications relaying. Taking advantage of such capabilities requires concurrent resource control of the handheld’s computational and communications capacities. Virtualization platforms, such as the Xen system, have opened the possibility of multiplexing a handheld device in useful and unobtrusive ways, as personal applications can be used while additional services such as decentralized communications are also in operation. The purpose of this project is to experimentally demonstrate the ability of modern smartphone units to support a programmable network environment. We attempt to validate the system with a series of measurement experiments which demonstrate concurrent use of two operating systems, each using computational and network resources, in two virtual machines. Moreover, we demonstrate an acceptable level of user performance while maintaining a MANET using a programmable network router

Organic molecular and inorganic isotope records of Cenozoic topography, ecosystem and climate evolution of the Southern Central Andes

The Andes are part of the longest mountain range on earthand their evolution has influenced global climate,weathering, and ecosystems since the Cretaceous. Weanalyzed the distribution and δ2H and δ13C of plant-derivedorganic biomarkers, the δ2H of volcanic glass, and thedistribution of soil-derived glycerol dialkyl glyceroltetraethers from Cenozoic sediments in the Malargüe Basinof Argentina (~35°S). Organic molecular and inorganic datawere measured to reconstruct Cenozoic changes inprecipitation isotopes, temperature, moisture deficit, andecosystems on the eastern flank of the Southern CentralAndes. Two variables (precipitation isotopes andtemperature) are strongly related to the topography of anorogen through isotopic distillation of precipitation duringrainout and changes in temperature with elevation.However, molecular biomarkers also provide keyinformation about climate and aridity through time. Weshow that organic biomarker and volcanic glass δ2H datafrom the Malargüe basin record late Cenozoic reduction oforographic lifting of airmasses associated with localdowndrop of the basin. In addition, molecular data reflectlong-term shifts in moisture deficit and plant water stressthat are consistent with regional patterns of changingclimate and aridity due to late Cenozoic cooling. Soilderivedtetraether lipid records mirror the patterns observedin organic molecular and inorganic isotope data, yet recordtemperatures that are unrealistic. These data highlight thecomplexity of universally applying the soil GDGT proxy toall terrestrial systems. In total, combined organic andinorganic data highlight the importance of multi-proxyrecords to produce a coherent representation of long-termecosystem and climate change in a region impacted byevolving climatic and tectonic boundary conditions.Fil: Hren, Michael. University of Connecticut; Estados UnidosFil: Brandon, Mark Thomas. University of Yale; Estados UnidosFil: Fennell, Lucas Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Smolen, Jonathan. University of Connecticut; Estados UnidosFil: Super, James. University of Yale; Estados UnidosGoldschmidt MeetingEstados UnidosGeochemical SocietyEuropean Association of Geochemistr

30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic – The GENEVA study

Background: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. Objectives: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. Results: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2, respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. Conclusions: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients

30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data

Background There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien-Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts

30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic - The GENEVA study.

BACKGROUND Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. OBJECTIVES This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. METHODS This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. RESULTS One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m , respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. CONCLUSIONS MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients

Safety and feasibility of revisional bariatric surgery following Laparoscopic Adjustable Gastric Band - Outcomes from a large UK private practice.

BACKGROUND Revisional bariatric surgery is unavoidable in a proportion of patients. Despite its need, the development of this speciality has been hampered by its complexity and preferred delivery in institutional set ups. Although primary bariatric surgery can be delivered in the private sector; safety and feasibility of revisional bariatric surgery remains unexplored in this setting. MATERIALS AND METHODS Patients undergoing revisional bariatric surgery following previous Laparoscopic Adjustable Gastric Band (LAGB) between 2008 and 2019 at a single private bariatric unit with a minimum follow up of at least 6 months were included. The primary aim was safety outcomes and 30-day morbidity. RESULTS 178 patients with BMI of 45.6 ± 8.2 kg/m underwent revisional bariatric surgery. One stage conversion was performed for 86.5% of the cases. At 9.5 ± 5.3 months follow up, BMI and percentage excess BMI loss were 31.8 ± 6.2 kg/m and 62.6 ± 40% respectively. There was no mortality, and the major complication rate was 2.8%. There was no statistically significant difference in the incidence of complications based on one-stage vs. two-stage conversion (p = 0.52). There were no differences in weight loss outcomes post-revisional surgery according to the indication for revision (p = 0.446) or weight loss following primary surgery (p = 0.12). CONCLUSION Revisional bariatric surgery can be delivered safely in the private sector with good outcomes. One-stage conversions are feasible and do not detrimentally affect the morbidity of the procedure or the weight loss outcomes. More importantly, success following revisional surgery is independent of the indication for revision and weight loss outcomes following primary surgery